I got into each mesh technology for specific devices. Home Assistant supports them all and they seem to coexist just fine in my use case.

I have a small to medium setup with only a few simple automations and a focus on voice control and scheduling

Preference

• Thread - given Apple, Amazon, and Google support and the standardization work, I expect this to be the future. Eventually. But I’m getting impatient. If I’m buying a device, I prefer Thread but usually it’s not yet
• z-Wave - my first, and most devices. Basically this was what was most available at local stores when I started. No complaints
• Zigbee - by far the biggest selection of simple, cheap sensors. I need to more of those
• all too much is WiFi but I try to avoid

But it also helps that my approach is generally switches and outlets. Hard-wired, predictable network, tend to be repeaters. I have comparatively fewer leaf nodes.

So for example a few years back I got a z-wave IR blaster to control a mini-split AC because at the time I mostly used z-wave. I already had a z-wave light switch in the same room, acting as a repeater, so no worries about connectivity. Now I have both z-wave and Zigbee light switches in that room so expect both meshes to be strong for any future devices